CORSET and GASP combiningV.M. Voskressencki, E.M. Kozulin
Flerov Laboratory of Nuclear Reaction, JINR, Dubna, Russia
Double-arms time-of-flight position-sensitive spectrometer CORSET for the correlated
measurements of the fission-like products of nuclear reaction.
Time resolution 120 - 150 psMass resolution ~ 2 amuAngular resolution ± 0.30
Position resolution less 1mm
GASP Configuration IThe 40 germanium detectors are placed at 27 cm from the target position
and cover a total solid angle of 10% corresponding to a total absolutephotopeak efficiency of 3% at a gamma-ray energy of 1332 keV.
For the 60Co source the Compton suppressed spectra have a mean P/T ratio of 60-65 %. The average energy resolution at 1332 keV is better than
2.3 keV and the average relative efficiency about 82%.. A filter, made of 80 BGO cristals acts as a active collimator
and measures the total energy and multiplicity of the gamma cascade.
+
BGO multiplicity
CORSET as a trigger devicein some experiments
CORSET+DEMON CORSET+DEMON+HENDES
DEMON detectors
HENDES detectors
Na-I gamma detectors
Vacuum chamber with CORSET detectors
Vacuum chamber with CORSET detectors
The physics applications imply the necessary attributes for ancillary devices :
• minimum interference with γ-detection (low mass – to minimize absorption and scattering of γ-rays)
• a count rate capability not limiting the data rate of the γ-array
• maximum detection efficiency • high angular resolution • optimal time resolution (if in use Time-of-Flight method)• changing detector’s position without chamber
deterioration
Coordinategrid
SMD preamplifierHV divider
target
MCP assembling
Electrostatic mirrorEntrance window withcarbon foil
MCPEntrancemylar(Au) foil
80
100
80
12
glass fibrelaminate frames
Start-Stop assambling
Organization of data acquisition
target
2
13
5
Start1
Start2
Stop 2
Stop 1
x2, y2
beam
x1, y1
Acquired parameters:1 – tof 12 – tof 23 – tofL14 – tof L25 – ∆Tstart
+ x1,x2,y1,y2+ E1-E4+ counters+ QDC channel for each detector
4
Electronic scheme
SCD monitorsE1,E2, E3,E4
• Flight path about 8 cm in each arm• Delay between event in target and signal from subsidence scheme about 100ns• Count rate on start detector up to 100kHz• Count rate in coincidence with stop detector up to several kHz
CORSET arrangement inside GASP
Startdetectors
StopDetectors
FRABA ABSOLUTE ROTARY ENCODER SSI PROGRAMMABLE( AWC58 12 – 1 – YGP0SL01KW)
PORTESCAP DC motorEscap 22V28-208E+ Gearbox escap RG1/9 (810)high vacuum execution
Targets
PORTESCAP DC motorEscap 22V28-208E+ Gearbox escap R22 (641)high vacuum execution
Position sensitivesensor
Realized construction
Target unit
CORSET detectors on support ring with servo-mechanism
Control unit
CORSET as a selective device for GASP1. Possibility to select the
reaction of interest(on picture: 48Ca + 238U reaction with some
impurities of Mo and W in target )
2. Possibility to select the reaction channel
Fusion-fissionQuasi-fission
Elastically scattered nuclei from target and beam
Deep inelastic reactions
3. Doppler correction of γ-rays, emitted in a flight
GASP for investigation of multimodal fission and quasifission
Understanding the fusion dynamics of two complex nuclei and evolution from a di-nuclear system to compound nucleus
formation.
Get information about γ-rays1. multiplicities
2. energy spectra 3. angle distribution
50 100 150 2000
50
100
150
150
200
250
300
TKE
, MeV
64Ni +186W → 250NoE*=31.5 MeV
Mass / u
N=82Z=50
N=50
Cou
nts
MED for the reaction 64Ni+185W→250No. The top plot ismass-TKE matrix, the bottom one is the mass distribution.
Possible CORSET pertormance buildup for GASP
motor andpotentiometer forvertical movement
motor andpotentiometer forrotating
motor andpotentiometer forstart-stopmovement
start-stop
detectors
supportrings
target holder
SCD monitors
• Increase area of stop detectors from 24 cm2 to 50 cm2
• Rebuild support ring• Upgrade target unit• Make control fully
automated from PC
Top Related